--- title: "SMA Solar STP 12-50 (Sunny Tripower X 12) Grid-tie Inverter: Specs & Datasheet | ComparePV" description: "SMA Solar STP 12-50 (Sunny Tripower X 12) 12 kW grid-tie inverter. Specs: 97.6% European efficiency, 3 MPPT, 1000 V max DC input, 35.0 kg, 5 yrs warranty." source: "https://comparepv.com/inverter/sma-solar-stp-12-50-sunny-tripower-x-12" updated: 2026-01-16 --- # SMA Solar STP 12-50 (Sunny Tripower X 12) ## Identity - **Manufacturer:** SMA Solar - **Model:** STP 12-50 (Sunny Tripower X 12) - **Series:** Sunny Tripower X - **Rated AC power:** 12 kW - **Type:** Grid-tie - **Phases:** Three-phase ## How it compares Compared against 266 inverters from 6 to 12 kW. Ranks are within that class. | Measure | This inverter | Class median | Standing | Rank in class | | --- | --- | --- | --- | --- | | European efficiency | 97.6% | 97.6% | Typical | 86 | | MPPT trackers | 3 | 2 | Strong - top 13% | 6 | | Max DC input voltage | 1000 V | 1000 V | Typical | 59 | | Weight per kW | 2.9 | 2.3 | Typical | 177 | | Warranty | 5 yrs | 5 yrs | Typical | 39 | ## Specification ### AC output - **Rated AC power:** 12 kW - **Max apparent power:** 12.00 kVA - **Phases:** Three-phase - **Nominal AC voltage:** 230 V - **Max AC current:** 20.0 A - **Grid frequency:** 50 Hz - **Power factor:** 1 at rated power; adjustable displacement PF: 0 overexcited to 0 underexcited - **Harmonic distortion (THD):** 3.0 % ### PV input - **Max DC input power:** 18.00 kW - **Max DC voltage:** 1000 V - **MPPT voltage range:** 150 to 1000 V - **Start-up voltage:** 188 V - **MPPT trackers:** 3 - **Max input current per MPPT:** 24.0 A - **Max short-circuit current per MPPT:** 37.5 A ### Efficiency - **European efficiency:** 97.6 % - **Max efficiency:** 98.2 % ### Physical - **Dimensions:** 762 × 728 × 266 mm - **Weight:** 35.0 kg - **Enclosure:** IP65 - **Cooling:** forced-air - **Noise:** 59 dB - **Operating temperature:** -25 to 60 °C - **Max humidity:** 100 % ### Connectivity and protection - **Interfaces:** Wi-Fi, Ethernet, Display - **Protocols:** SMA Modbus, SunSpec Modbus, Speedwire, RS485 (client, optional) - **Protection:** AFCI, DC switch, Surge protection ### Warranty and certificates - **Warranty:** 5 years - **Certifications:** AS4777.2:2020, C10/C11:2019 & V1:2020 LV&MV, CE, EIFS 2018:2, EN 50549-1/-2:2018, EN50549-10:2022, EREC G99/1-8:2021 Type A, IEC 61727, IEC 62109-1/-2, IEC 62116, NA/EEA-NE7, NBR 16149:2013, NRS 097-2-1:2017, PSE 2018, TED/749/2020 inkl. NTS2.1, TOR Erzeuger Typ A:2019-12, UKCA, UNE 217002:2020, VDE 0126-1-1:2013/A1:2012, VDE-AR-N 4105:2018 incl. PAV,E, VDE-AR-N 4110:2018, VFR 2019, CEI 0-16/0-21:2019 & V1:2020 ### Pros - **3 MPPT + ShadeFix Without Module Optimizers** - Three independent MPPT trackers operating across a 150-800 V DC input range allow strings of different orientations and lengths to be combined within a single inverter. SMA's ShadeFix algorithm performs partial-shading optimization directly inside the inverter, eliminating the need for expensive module-level power electronics such as those required by SolarEdge solutions. - **Up to 98% Efficiency (CEC/Peak)** - The STP 25-50 achieves a peak efficiency of 98% (CEC rating for the US variant, confirmed in SMA's official datasheet), while the STP 20-50 reaches 97.9%. These figures place the series among the top-performing three-phase grid-tied string inverters in the premium segment - on par with the Fronius Symo GEN24 at 98.0-98.1% - translating into measurable energy yield gains under the partial-load conditions typical of Polish irradiation profiles. - **Integrated System Manager (ennexOS)** - The inverter simultaneously acts as a system hub: it centrally manages up to five SMA Speedwire devices, supports dynamic active and reactive power control (SMA Dynamic Power Control), and provides direct access to Sunny Portal - with no additional data logger or communication gateway required. - **Built-In AFCI (SMA ArcFix)** - DC arc-fault circuit interruption is included as a standard feature across the series at no extra cost. The functionality meets applicable safety standards including IEC 63027 and reduces the risk of installation fires - a critical consideration for rooftop commercial installations where insurers are increasingly mandating certified AFCI protection. - **200% DC Oversizing and Compatibility with Next-Generation Modules** - A permissible DC/AC ratio of up to 200%, combined with support for input currents of up to 24 A Imp / 37.5 A Isc per string, enables system designs using high-power HJT and TOPCon modules (550-700 Wp) without derating constraints - maximizing energy yield while minimizing the total number of inverters required. ### Cons - **Standard Warranty Only 5 Years** - The Sunny Tripower X carries a 5-year standard warranty (confirmed via sma-service.com), compared to SolarEdge's 12-year standard warranty on its three-phase inverters. Extending SMA coverage to 10, 15, or 20 years requires paid registration, increasing the total cost of ownership of the installation. - **Significant Price Premium vs. Asian Tier-1 Competitors** - The STP X 12 kW retails in Poland at approximately 4,500-5,000 PLN, while comparable models - the Huawei SUN2000-12KTL-M2 and Sungrow SG12RT - are available for 2,500-3,500 PLN, a gap of 40-70%. In commercial-scale projects where inverter count is high, this price disparity places a material burden on overall CAPEX. ## About this series SMA Solar Technology's Sunny Tripower X series is a **three-phase grid-tie inverter** designed for large residential installations and the commercial segment, where project flexibility and fast service matter. Its key advantage is the integrated **System Manager**, which simplifies installation monitoring and enables centralized operation and management of multiple devices within a single network. Thanks to **three MPPTs**, it’s easier to connect strings with different roof orientations, lengths, or sun exposure conditions, improving performance even under partial shading. High European efficiency means more energy in real-world operating conditions typical for Poland - not just in the lab, but with variable temperatures and dynamic loads. Monitoring and communication are ready for modern implementations - via Ethernet and the Sunny Portal (ennexOS) ecosystem, and WiFi is especially useful during configuration. Additional safety features, such as **arc fault detection (AFCI)**, enhance installation protection. The series is certified to meet connection requirements (including EN 50549), and the standard warranty is extendable. ## Questions ### What types of installations is the SMA Sunny Tripower X series suited for, and will it work in a residential setting? The Sunny Tripower X is a three-phase grid-tied inverter available in 12, 15, 20, and 25 kW power ratings, designed primarily for large residential installations (above 10 kW) and commercial facilities. It requires a three-phase grid connection and is therefore not suitable for standard single-phase residential systems. If you have a large building with a three-phase meter and are planning a PV system above 10 kWp, this series represents the optimal choice. ### How does SMA ShadeFix improve energy yield under partial shading conditions in a Sunny Tripower X installation? ShadeFix is a maximum power point tracking algorithm developed by SMA that works in conjunction with three independent MPPT inputs. Unlike conventional optimization approaches, ShadeFix scans the entire DC voltage range to identify the global maximum power point, eliminating the need for external power optimizers. This translates into measurable gains in energy yield for installations affected by chimneys, dormers, or roof sections with varying orientations. ### What is the standard warranty on the SMA Sunny Tripower X inverter, and can it be extended? The standard manufacturer warranty for the Sunny Tripower X series is 5 years. SMA offers the option to extend coverage to 10, 15, or even 20 years through the SMA Smart Connected package or additional service agreements. It is worth noting that purchases made through authorized SMA partners in Poland are subject to the same warranty policy that applies across the rest of Europe. ### What does the integrated System Manager in the Sunny Tripower X provide, and do I need a separate monitoring device? The built-in System Manager enables a single inverter to manage an installation comprising up to five SMA Speedwire devices and one Energy Meter, without the need to purchase a separate data logger. Monitoring is available via the Sunny Portal (ennexOS) platform over Ethernet, while Wi-Fi simplifies configuration during commissioning. For larger systems requiring more advanced energy management, an additional SMA Data Manager M is recommended. ### Does the SMA Sunny Tripower X comply with Polish grid connection requirements, and will it receive approval from the distribution system operator? Yes, the Sunny Tripower X series is certified in accordance with EN 50549 and VDE-AR-N 4105/4110, which form the basis of the grid connection requirements applied by Polish distribution system operators (DSOs). The inverter supports active and reactive power control (SMA Dynamic Power Control), which facilitates compliance with the grid connection conditions issued by operators such as Tauron, Energa, and PGE. ### How does the SMA Sunny Tripower X differ from the older Sunny Tripower series (without the X designation), and is the price premium justified? The key differences include: three MPPT inputs instead of two found in previous Tripower models, a built-in System Manager that eliminates the need for a separate data logger, support for the ennexOS platform in place of the legacy Sunny Portal, and an integrated arc-fault circuit interrupter (AFCI) function - SMA ArcFix - that enhances installation safety. For new installations above 10 kW, the X series represents the current SMA standard and is clearly the superior option compared to the legacy TL models being phased out. ## Datasheet [Manufacturer datasheet (PDF)](https://comparepv.com/datasheets/inverters/stpxx-50-ds-en-23-7036ff2db360.pdf) ## Alternatives | Inverter | Rated AC | Euro efficiency | MPPT | Weight | Difference | | --- | --- | --- | --- | --- | --- | | [Growatt MOD 12KTL3-X](https://comparepv.com/inverter/growatt-mod-12ktl3-x) | 12 kW | 98.2% | 2 | 14.0 kg | +0.6 pp efficiency, -1 MPPT, 21.0 kg lighter | | [Growatt MOD 12KTL3-X2(Pro)](https://comparepv.com/inverter/growatt-mod-12ktl3-x2-pro) | 12 kW | 98.2% | 2 | 15.6 kg | +0.6 pp efficiency, -1 MPPT, 19.4 kg lighter | | [Sungrow SG12KTL-M](https://comparepv.com/inverter/sungrow-sg12ktl-m) | 12 kW | 98.1% | 2 | 20.0 kg | +0.5 pp efficiency, -1 MPPT, 15.0 kg lighter | | [Sungrow SG12RT-20](https://comparepv.com/inverter/sungrow-sg12rt-20) | 12 kW | 98.1% | 2 | 17.0 kg | +0.5 pp efficiency, -1 MPPT, 18.0 kg lighter | | [GoodWe GW12KLN-DT](https://comparepv.com/inverter/goodwe-gw12kln-dt) | 12 kW | 98.1% | 2 | 26.0 kg | +0.5 pp efficiency, -1 MPPT, 9.0 kg lighter | | [Huawei SUN2000-12KTL-M0](https://comparepv.com/inverter/huawei-sun2000-12ktl-m0) | 12 kW | 98.0% | 2 | 25.0 kg | +0.4 pp efficiency, -1 MPPT, 10.0 kg lighter | | [Huawei SUN2000-12KTL-M2](https://comparepv.com/inverter/huawei-sun2000-12ktl-m2) | 12 kW | 98.0% | 2 | 25.0 kg | +0.4 pp efficiency, -1 MPPT, 10.0 kg lighter | | [SOFAR 12KTLX-G3](https://comparepv.com/inverter/sofar-solar-sofar-12ktlx-g3) | 12 kW | 98.0% | 2 | 18.0 kg | +0.4 pp efficiency, -1 MPPT, 17.0 kg lighter | --- Source: https://comparepv.com/inverter/sma-solar-stp-12-50-sunny-tripower-x-12